The purpose of this multicenter study is to determine the prevalance of soy allergy in children less than 3 years of age with IgE-mediated cow's milk allergy (CMA). All children with milk challenge-confirmed CMA are placed on soy formula & monitored for at least one year for development of allergic symptoms. Suspected symptoms are investigated with blinded challenges to soy. Patients are being enrolled at 4 centers and no results are yet available.